Nitric acid production unit and device

Abstract

The utility model discloses a nitric acid production unit and device, and relates to the technical field of nitric acid production equipment. The nitric acid production unit comprises an air compressor, a nitric oxide compressor, an expansion machine and a driving module, the driving module comprises a driving machine and at least two first-stage transmission shafts, the at least two first-stage transmission shafts are connected with the driving machine and provided with at least three first-stage connecting ends, and the first-stage connecting ends are connected with the driving machine. And the first-stage connecting end is correspondingly connected with one or two of the air compressor, the nitrogen oxide compressor and the expansion machine. The nitric acid production unit provided by the utility model is more compact in structure and smaller in size.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of nitric acid production equipment, in particular to a nitric acid production unit and device. BACKGROUND

[0002] The existing nitric acid production unit is composed of an air compressor, a nitric oxide compressor, an expander and a steam turbine, a variable speed gearbox is arranged between the steam turbine and the air compressor to ensure that each device operates at the required speed, and each rotor is connected together through a shaft coupling between each device and between the device and the variable speed gearbox. The entire unit has a large axial length, which causes the entire unit to have a large volume and a large floor area after installation. CONTENT OF THE UTILITY MODEL

[0003] Therefore, the present application provides a nitric acid production unit and device to solve one of the technical problems in the prior art.

[0004] To achieve the above-mentioned purpose, the technical scheme adopted by the present application is as follows:

[0005] In a first aspect, the present application provides a nitric acid production unit, comprising:

[0006] an air compressor;

[0007] a nitric oxide compressor;

[0008] an expander;

[0009] a drive module comprising a drive machine and at least two primary transmission shafts, the at least two primary transmission shafts being respectively connected to the drive machine, the at least two primary transmission shafts being provided with at least three primary connection ends, and each primary connection end being connected to one or two of the air compressor, the nitric oxide compressor and the expander;

[0010] The drive module comprises the drive machine, a first primary transmission shaft and a second primary transmission shaft, the first primary transmission shaft and the second primary transmission shaft being respectively connected to the drive machine, the first primary transmission shaft being provided with at least two primary connection ends, and the second primary transmission shaft being provided with at least one primary connection end, each primary connection end being connected to one or two of the air compressor, the nitric oxide compressor and the expander.

[0011] In one embodiment of the first aspect, the drive module further comprises:

[0012] The first gearbox comprises a first gearbox shaft, a first secondary transmission shaft and a second secondary transmission shaft, the first gearbox shaft is provided with two first level connection ends and an input end, the input end of the first gearbox shaft is connected with the first primary transmission shaft, one of the first level connection ends of the first gearbox shaft is connected with the first secondary transmission shaft, and the other first level connection end is connected with the second secondary transmission shaft.

[0013] In one of the embodiments of the first aspect, the driving module further comprises:

[0014] The second gearbox comprises a second gearbox shaft and a third secondary transmission shaft, the second gearbox shaft is provided with one first level connection end and an input end, the input end of the second gearbox shaft is connected with the second primary transmission shaft, and the first level connection end of the second gearbox shaft is connected with the third secondary transmission shaft.

[0015] Or;

[0016] The second gearbox comprises a second gearbox shaft, a third secondary transmission shaft and a fourth secondary transmission shaft, the second gearbox shaft is provided with two first level connection ends and an input end, the input end of the second gearbox shaft is connected with the second primary transmission shaft, one of the first level connection ends of the second gearbox shaft is connected with the third secondary transmission shaft, and the other first level connection end is connected with the fourth secondary transmission shaft.

[0017] In one of the embodiments of the first aspect, the air compressor comprises at least one air compressor rotor;

[0018] The nitrogen oxide compressor comprises at least one nitrogen oxide compressor rotor;

[0019] The expander comprises at least one expander rotor, each rotor of the air compressor, the nitrogen oxide compressor and the expander is connected with one of the first secondary transmission shaft, the second secondary transmission shaft and the third secondary transmission shaft.

[0020] In one of the embodiments of the first aspect, the first secondary transmission shaft, the second secondary transmission shaft and the third secondary transmission shaft are each provided with two secondary level connection ends, and the first secondary transmission shaft, the second secondary transmission shaft and the third secondary transmission shaft are provided with six secondary level connection ends in total.

[0021] In one of the embodiments of the first aspect, the air compressor comprises a first air compressor rotor and a second air compressor rotor;

[0022] The nitrogen oxide compressor comprises a first nitrogen oxide compressor rotor and a second nitrogen oxide compressor rotor;

[0023] The expander comprises a first expander rotor and a second expander rotor, wherein,

[0024] The first air compressor rotor is connected with one of the six secondary connection terminals, the second air compressor rotor is connected with one of the remaining six secondary connection terminals, the first nitrogen oxide compressor rotor is connected with one of the remaining six secondary connection terminals, the second nitrogen oxide compressor rotor is connected with one of the remaining six secondary connection terminals, the first expander rotor is connected with one of the remaining six secondary connection terminals, and the second expander rotor is connected with one of the remaining six secondary connection terminals.

[0025] In one of the embodiments of the first aspect, the driving machine is an electric machine; the air compressor and the nitrogen oxide compressor are both centrifugal compressors; and the expander is a centripetal or axial expander.

[0026] In one of the embodiments of the first aspect, the air compressor and the nitrogen oxide compressor are both in a two-stage or more compression structure, the number of the air compressor rotors is at least two, and the number of the nitrogen oxide compressor rotors is at least two.

[0027] The expander is in a two-stage or more expansion structure, and the number of the expander rotors is at least two.

[0028] In one of the embodiments of the first aspect, the air compressor rotor, the nitrogen oxide compressor rotor and the expander rotor are all not coaxial with the driving machine.

[0029] In the second aspect, the embodiments of the present application further provide a nitric acid production device, which comprises the nitric acid production unit in any of the above embodiments.

[0030] An oxidation furnace connected with the air compressor;

[0031] A heat exchanger connected with the nitrogen oxide compressor and the oxidation furnace;

[0032] An absorption tower connected with the nitrogen oxide compressor and the expander.

[0033] Compared with the prior art, the application has the beneficial effects that the application provides a nitric acid production unit, which comprises a driving module, an air compressor, a nitrogen oxide compressor and an expander. The driving module comprises a driving machine and at least two primary transmission shafts, and the at least two primary transmission shafts are connected with the driving machine respectively, so that the driving machine has multiple output ends. The at least two primary transmission shafts are provided with at least three primary connection ends, and the primary connection ends are connected with one or two of the air compressor, the nitrogen oxide compressor and the expander correspondingly. In this way, the air compressor, the nitrogen oxide compressor and the expander are connected with the multiple output ends of the driving machine through the at least two primary transmission shafts as accessories, the axial length of the nitric acid production unit is shortened, and the whole unit structure is more compact, has high integration degree and is more compact in size. BRIEF DESCRIPTION OF DRAWINGS

[0034] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some of the embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0035] Figure 1 A structure schematic diagram of a nitric acid production unit in the related art is shown;

[0036] Figure 2 A structure schematic diagram of a nitric acid production unit in some embodiments of the application is shown;

[0037] Figure 3 A structure schematic diagram of a nitric acid production unit in some embodiments of the application is shown;

[0038] Figure 4 A structure schematic diagram of a nitric acid production unit in some embodiments of the application is shown;

[0039] Figure 5 A structure schematic diagram of a nitric acid production unit in some embodiments of the application is shown;

[0040] Figure 6 A structure schematic diagram of a nitric acid production unit in some embodiments of the application is shown;

[0041] Figure 7 A structure schematic diagram of a nitric acid production unit in some embodiments of the application is shown;

[0042] Figure 8 A structure schematic diagram of a nitric acid production unit in some embodiments of the application is shown;

[0043] Figure 9Fig. 8 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0044] Figure 10 Fig. 9 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0045] Figure 11 Fig. 10 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0046] Figure 12 Fig. 11 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0047] Figure 13 Fig. 12 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0048] Figure 14 Fig. 13 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0049] Figure 15 Fig. 14 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0050] Figure 16 Fig. 15 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0051] Figure 17 Fig. 16 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0052] Figure 18 Fig. 17 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0053] Figure 19 Fig. 18 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0054] Figure 20 Fig. 19 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0055] Figure 21 Fig. 20 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0056] Figure 22 Fig. 21 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0057] Figure 23 Fig. 22 shows a structural schematic diagram of a nitric acid production unit in some embodiments of the present application;

[0058] Figure 24 Fig. 23 shows a structural schematic diagram of a nitric acid production unit according to some embodiments of the present application;

[0059] Figure 25 Fig. 24 shows a structural schematic diagram of a nitric acid production unit according to some embodiments of the present application;

[0060] Figure 26 Fig. 25 shows a structural schematic diagram of a nitric acid production unit according to some embodiments of the present application;

[0061] Figure 27 Fig. 26 shows a structural schematic diagram of a nitric acid production unit according to some embodiments of the present application;

[0062] Figure 28 Fig. 27 shows a structural schematic diagram of a nitric acid production unit according to some embodiments of the present application;

[0063] Figure 29 Fig. 28 shows a structural schematic diagram of a nitric acid production unit according to some embodiments of the present application;

[0064] Figure 30 Fig. 29 shows a structural schematic diagram of a nitric acid production unit according to some embodiments of the present application;

[0065] Figure 31 Fig. 30 shows a structural schematic diagram of a nitric acid production unit according to some embodiments of the present application;

[0066] Figure 32 Fig. 31 shows a structural schematic diagram of a nitric acid production unit according to some embodiments of the present application;

[0067] Figure 33 Fig. 32 shows a structural schematic diagram of a nitric acid production unit according to some embodiments of the present application.

[0068] Main element symbol explanation:

[0069] 1000 - nitric acid production unit; 100 - nitric acid production unit; 200 - oxidation furnace; 300 - heat exchanger; 400 - absorption tower;

[0070] 110 - driving module; 111 - driving machine; 112 - first gearbox; 113 - second gearbox; 114 - first level connection end; 115 - second level connection end; 1111 - first first level transmission shaft; 1112 - second first level transmission shaft; 1121 - first variable speed shaft; 1131 - second variable speed shaft; 1122 - first second level transmission shaft; 1123 - second second level transmission shaft; 1132 - third second level transmission shaft; 1133 - fourth second level transmission shaft;

[0071] 120 - air compressor; 130 - nitric oxide compressor; 140 - expander; 121 - first air compressor rotor; 122 - second air compressor rotor; 131 - first nitric oxide compressor rotor; 132 - second nitric oxide compressor rotor; 141 - first expander rotor; 142 - second expander rotor; 143 - third expander rotor. DETAILED DESCRIPTION

[0072] Embodiments of the present application are described in detail below with reference to examples illustrated in the accompanying drawings, in which the same or similar components have the same or similar designations throughout the various figures and identical or similar components are denoted with the same or similar reference numerals. The embodiments described below are examples only, and are not intended to limit the present application.

[0073] In addition, the terms "first", "second", etc. are used only for descriptive purposes and should not be construed as implying or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more features. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise explicitly specified and limited.

[0074] In the present application, unless otherwise explicitly specified and limited, the terms "connected", "connected" and the like should be broadly understood, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0075] Embodiment 1

[0076] Please refer to Figure 1 The existing nitric acid production unit is composed of an air compressor, a nitric oxide compressor, an expander and a turbine connected in series. Specifically, the rotor of the turbine and one of the gear shafts of the variable speed gear box are connected through a shaft coupling, and the other gear shaft of the variable speed gear box and the rotors of the air compressor, the nitric oxide compressor and the expander are connected together through three shaft couplings. The transmission shaft of the rotor system composed of the gear shaft of the variable speed gear box, the rotor of the air compressor, the rotor of the nitric oxide compressor and the rotor of the expander is very long, resulting in a large volume of the entire unit.

[0077] In view of the above problems, such as Figure 2As shown, the embodiment of the present application provides a nitric acid production unit 100, mainly used for producing nitric acid. The nitric acid production unit 100 comprises an air compressor 120, a nitric oxide compressor 130, an expander 140 and a driving module 110.

[0078] The air compressor 120, the nitric oxide compressor 130, the expander 140 and the driving module 110 of the present application jointly constitute an integrated gear speed-up assembly type unit as the power driving equipment of the entire nitric acid device.

[0079] The driving module 110 comprises a driving machine 111 and at least two primary transmission shafts, and the at least two primary transmission shafts are respectively connected with the driving machine 111, so that the driving machine 111 has multiple output ends.

[0080] The at least two primary transmission shafts are provided with at least three primary connection ends 114, and each primary connection end 114 is connected with one or two of the air compressor 120, the nitric oxide compressor 130 and the expander 140. In this way, the air compressor 120, the nitric oxide compressor 130 and the expander 140 are connected with the multiple output ends of the driving machine 111 as accessories through the at least two primary transmission shafts, so that the axial length of the nitric acid production unit 100 is shortened, and the entire unit structure is more compact and has high integration and small volume.

[0081] In the embodiment, the driving module 110 comprises the driving machine 111, a first primary transmission shaft 1111 and a second primary transmission shaft 1112.

[0082] The first primary transmission shaft 1111 and the second primary transmission shaft 1112 are respectively connected with the driving machine 111, so that the driving machine 111 has two output ends.

[0083] The first primary transmission shaft 1111 is provided with at least two primary connection ends 114, and the second primary transmission shaft 1112 is provided with at least one primary connection end 114. Each primary connection end 114 is connected with one or two of the air compressor 120, the nitric oxide compressor 130 and the expander 140. In this way, the air compressor 120, the nitric oxide compressor 130 and the expander 140 are respectively connected with the driving machine 111 as accessories through the first primary transmission shaft 1111 and the second primary transmission shaft 1112, so that the transmission shaft distance of the nitric acid production unit 100 is shortened, and the entire unit structure is more compact, has high integration and small volume.

[0084] It should be noted that the driving machine 111 is an electric machine or a steam turbine. In the embodiment, the driving machine 111 is preferably an electric machine, and in other embodiments, the driving machine 111 is a steam turbine. It can be understood that the steam turbine is driven by steam and must be provided with a gas source, while the electric machine can be connected with a power source, and the electric machine has a wider application range.

[0085] In some embodiments, the air compressor 120 and the nitric oxide compressor 130 are both centrifugal compressors, and the expander 140 is a centripetal or axial expander. The air compressor 120, the nitric oxide compressor 130 and the expander 140 are all rotary turbomachinery, which generates centrifugal force or centripetal force by rotation of impellers to realize work.

[0086] In one embodiment, the drive module 110 further comprises a first gearbox 112 and a second gearbox 113. The first gearbox 112 and the second gearbox 113 are respectively arranged at both ends of the motor and serve as the basis for connecting various functional modules.

[0087] The first gearbox 112 comprises a first variable speed shaft 1121, a first secondary transmission shaft 1122 and a second secondary transmission shaft 1123.

[0088] The first variable speed shaft 1121 is provided with two primary connection ends 114 and an input end. The input end of the first variable speed shaft 1121 is connected with the first primary transmission shaft 1111, and one of the primary connection ends 114 of the first variable speed shaft 1121 is connected with the first secondary transmission shaft 1122, and the other primary connection end 114 is connected with the second secondary transmission shaft 1123.

[0089] The second gearbox 113 comprises a second variable speed shaft 1131 and a third secondary transmission shaft 1132.

[0090] The second variable speed shaft 1131 is provided with one primary connection end 114 and an input end. The input end of the second variable speed shaft 1131 is connected with the second primary transmission shaft 1112, and the primary connection end 114 of the second variable speed shaft 1131 is connected with the third secondary transmission shaft 1132.

[0091] Alternatively, the second gearbox 113 comprises a second variable speed shaft 1131, a third secondary transmission shaft 1132 and a fourth secondary transmission shaft 1133.

[0092] The second variable speed shaft 1131 is provided with two primary connection ends 114 and an input end. The input end of the second variable speed shaft 1131 is connected with the second primary transmission shaft 1112, one of the primary connection ends 114 of the second variable speed shaft 1131 is connected with the third secondary transmission shaft 1132, and the other primary connection end 114 is connected with the fourth secondary transmission shaft 1133.

[0093] Specifically, the motor is coupled with the first variable speed shaft 1121 in the first gearbox 112 through a coupling, and the motor is coupled with the second variable speed shaft 1131 through another coupling.

[0094] The first variable speed shaft 1121 is connected with the first and second secondary transmission shafts 1122 and 1123 respectively to form a gear pair driven by the driving gear. The first variable speed gearbox 112 takes the first primary transmission shaft 1111 as the input shaft and takes the first and second secondary transmission shafts 1122 and 1123 as the two output shafts. The second variable speed gearbox 113 takes the second primary transmission shaft 1112 as the input shaft and takes the third and fourth secondary transmission shafts 1132 and 1133 as the two output shafts.

[0095] As shown in Figure 2 , one end of the motor is connected with the first variable speed shaft 1121 of the first variable speed gearbox 112 through a shaft coupling, so that the power output by the motor shaft is transmitted to the first variable speed shaft 1121 of the first variable speed gearbox 112, and then the power output by the motor is transmitted to the first and second secondary transmission shafts 1122 and 1123 in the first variable speed gearbox 112 through the first variable speed shaft 1121. It should be noted that the speed ratio (the ratio of the number of teeth of the large gear to the small gear) of the gear pair of the first and second variable speed gearboxes 112 and 113 can be set according to the rotor speed required by the air compressor 120, the nitrogen oxide compressor 130 and the expander 140 connected thereto.

[0096] In one embodiment, the air compressor 120 includes at least one air compressor rotor, the nitrogen oxide compressor 130 includes at least one nitrogen oxide compressor rotor, and the expander 140 includes at least one expander rotor. Each rotor of the air compressor 120, the nitrogen oxide compressor 130 and the expander 140 is connected with one of the first, second and third secondary transmission shafts 1122, 1123 and 1132. In this way, each rotor is connected with a secondary transmission shaft separately, so that the structure of the air compressor 120, the nitrogen oxide compressor 130 and the expander 140 connected with the motor is more compact.

[0097] Please continue to refer to Figure 1 In the related art, the other gear shaft of the variable speed gearbox and the rotors of the air compressor, the nitrogen oxide compressor and the expander are generally connected together through three shaft couplings, and the transmission shaft is very long. The rotor system rotates at a very high speed, and the stability and reliability of dynamics are a big test. At the same time, the long rotor structure combined by the multiple shaft couplings also has the problem of torsional vibration (referred to as torsional vibration). If the rotor dynamics is not well designed, the torsional vibration is easy to be too large, thereby causing the instability and damage of the entire rotor system and other major quality problems.

[0098] In view of the above problems, as shown in Figure 2As shown, in the embodiment, the first secondary transmission shaft 1122, the second secondary transmission shaft 1123 and the third secondary transmission shaft 1132 are each provided with two secondary connection ends 115, and the first secondary transmission shaft 1122, the second secondary transmission shaft 1123 and the third secondary transmission shaft 1132 are collectively provided with six secondary connection ends 115.

[0099] On the basis of the above, the air compressor 120 includes a first air compressor rotor 121 and a second air compressor rotor 122, the nitric oxide compressor 130 includes a first nitric oxide compressor rotor 131 and a second nitric oxide compressor rotor 132, and the expander 140 includes a first expander rotor 141 and a second expander rotor 142. Among them:

[0100] The first air compressor rotor 121 is connected with one of the six secondary connection ends 115, the second air compressor rotor 122 is connected with one of the remaining six secondary connection ends 115, the first nitric oxide compressor rotor 131 is connected with one of the remaining six secondary connection ends 115, the second nitric oxide compressor rotor 132 is connected with one of the remaining six secondary connection ends 115, the first expander rotor 141 is connected with one of the remaining six secondary connection ends 115, and the second expander rotor 142 is connected with one of the remaining six secondary connection ends 115.

[0101] By setting six secondary connection ends 115, and each secondary connection end 115 is connected with one of the first air compressor rotor 121, the second air compressor rotor 122, the first nitric oxide compressor rotor 131, the second nitric oxide compressor rotor 132, the first expander rotor 141 and the second expander rotor 142, the air compressor 120, the nitric oxide compressor 130 and the expander 140 are equivalent to being installed as accessories on the first transmission 112 or the second transmission 113, and the output shaft of the first transmission 112 or the second transmission 113 is the rotor of the air compressor 120, the nitric oxide compressor 130 and the expander 140, and no additional shaft coupling is needed, which shortens the transmission shaft distance of the rotor system of the application, and the entire unit is very compact and highly integrated.

[0102] In addition, since the rotors are not connected in series by the head-to-tail mode, but are connected in parallel by the gear pair matching mode of the two primary transmission shafts of the motor. Each rotor is the output shaft of the first transmission 112 or the second transmission 113. Such a structure greatly reduces the torsional vibration problem of the nitric acid production unit 100, and improves the stability and reliability of the entire nitric acid production unit 100.

[0103] It should be noted that in other embodiments, any one of the first secondary transmission shaft 1122, the second secondary transmission shaft 1123, and the third secondary transmission shaft 1132 can be provided with one or two secondary connection ends 115 to reduce the cost of the nitric acid production unit 100 and improve production efficiency.

[0104] The number of secondary connection ends 115 is the same as the number of air compressor rotors, nitrogen oxide compressor rotors, and expanders in actual production. The first gearbox 112 can be provided with one or two secondary transmission shafts, and the second gearbox 113 can also be provided with one or two secondary transmission shafts. The actual setting method can be set according to actual production, and there is no particular limitation.

[0105] For example, when only one air compressor rotor, one nitrogen oxide compressor rotor, and one expander are provided, the first secondary transmission shaft 1122 is provided with one secondary connection end 115, the second secondary transmission shaft 1123 is provided with one connection end, and the third secondary transmission shaft 1132 is provided with one secondary connection end 115. Each secondary connection end 115 is connected to one of the air compressor rotor, the nitrogen oxide compressor rotor, and the expander.

[0106] For example, when only one air compressor rotor, one nitrogen oxide compressor rotor, and one expander are provided, the first secondary transmission shaft 1122 is provided with one secondary connection end 115 or the second secondary transmission shaft 1123 is provided with one secondary connection end 115, and the third secondary transmission shaft 1132 is provided with two secondary connection ends 115. Each connection end is connected to one of the air compressor rotor, the nitrogen oxide compressor rotor, and the expander.

[0107] In one embodiment, one secondary connection end 115 of the third secondary transmission shaft 1132 is connected to the first expander rotor 141, and the other secondary connection end 115 is connected to the second expander rotor 142.

[0108] One secondary connection end 115 of the second secondary transmission shaft 1123 is connected to the first air compressor rotor 121, and the other secondary connection end 115 is connected to the second air compressor rotor 122.

[0109] One secondary connection end 115 of the first secondary transmission shaft 1122 is connected to the first nitrogen oxide compressor rotor 131, and the other secondary connection end 115 is connected to the second nitrogen oxide compressor rotor 132.

[0110] In this way, when the nitric acid production unit 100 is just started, the motor is mainly used to drive the air compressor 120 and the nitric oxide compressor 130 to compress the gas. When the nitric acid production unit 100 can provide high-temperature and high-pressure gas to drive the expander 140 to work, the work done by the expander 140 is used to supplement the required compression work (the power required by the air compressor 120 and the nitric oxide compressor 130 to compress the gas), thereby reducing the power consumption of the motor and improving the operation efficiency of the entire unit.

[0111] The motor and the expander 140 work as a power source and deliver energy to the air compressor 120 and the nitric oxide compressor 130 to provide compressed gas.

[0112] In some embodiments, the air compressor 120 and the nitric oxide compressor 130 are both two-stage or more compression structures, and the number of air compressor rotors is at least two, and the number of nitric oxide compressor rotors is at least two. That is, the air compressor 120 has at least two impellers, and the nitric oxide compressor 130 has at least two impellers.

[0113] The expander 140 is a two-stage or more expansion structure, and the number of expander rotors is at least two, that is, the expander 140 has at least two impellers.

[0114] In some embodiments, the air compressor rotor, the nitric oxide compressor rotor, and the expander rotor are not coaxial with the driving machine 111, so that the rotational speed of each rotor is not limited by the rotational speed of the driving machine 111, and a higher required working speed can be obtained according to the gear box speed ratio design, and the unit operating range is wider.

[0115] It should be noted that in the present embodiment, the expander 140 supplies the air compressor 120 and the nitric oxide compressor 130 by directly outputting mechanical work, thereby reducing the power consumption of the motor and improving the operation efficiency of the entire unit.

[0116] In other embodiments, the expander 140 can also supply the motor by directly outputting mechanical work, convert the mechanical work into electrical energy, and then the motor converts the electrical energy into mechanical work to supply the air compressor 120 and the nitric oxide compressor 130. However, the energy loss in the process of converting mechanical work of the expander 140 into electrical energy and then converting the electrical energy into mechanical work is higher than the energy loss of the expander 140 in the present embodiment, in which the mechanical work is directly transmitted from the expander 140 to the air compressor 120 and the nitric oxide compressor 130.

[0117] In the present embodiment, as shown in FIG. 1, the driving machine 111 is connected to the air compressor 120 and the nitric oxide compressor 130 through a gear box 112, and the expander 140 is connected to the air compressor 120 and the nitric oxide compressor 130 through a gear box 142. Figure 2As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142, the two secondary connection ends 115 of the second secondary drive shaft 1123 are respectively connected to the first air compressor rotor 121 and the second air compressor rotor 122, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132.

[0118] In other embodiments, exemplarily, such as Figure 3 As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first air compressor rotor 121 and the second air compressor rotor 122, the two secondary connection ends 115 of the second secondary drive shaft 1123 are respectively connected to the first expander rotor 141 and the second expander rotor 142, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132.

[0119] In other embodiments, exemplarily, such as Figure 4 As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132, the first expander rotor 141 and the second expander rotor 142, the two secondary connection ends 115 of the second secondary drive shaft 1123 are respectively connected to the first air compressor rotor 121 and the second air compressor rotor 122, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first expander rotor 141 and the second expander rotor 142.

[0120] In other embodiments, exemplarily, such as Figure 5 As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142, the two secondary connection ends 115 of the second secondary drive shaft 1123 are respectively connected to the first air compressor rotor 121 and the second nitrogen oxide compressor rotor 132, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second air compressor rotor 122.

[0121] In other embodiments, exemplarily, such as Figure 6As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the second nitrogen oxide compressor rotor 132 and the first air compressor rotor 121, the two secondary connection ends 115 of the second secondary drive shaft 1123 are respectively connected to the second expander rotor 142 and the first expander rotor 141, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second air compressor rotor 122.

[0122] Please refer to the following: Figure 7 to Figure 11 The second gearbox 113 includes a third secondary drive shaft 1132 and a fourth secondary drive shaft 1133, and increases the number of expander rotors. Specifically, the expander 140 includes a first expander rotor 141, a second expander rotor 142, and a third expander rotor 143.

[0123] In this way, when the nitric acid production unit 1000 can provide high-temperature and high-pressure gas to drive the expander 140 to do work, the expander 140 can output more power to supplement the compression work required in the unit (the power required by the air compressor 120 and the nitrogen oxide compressor 130 to compress the gas), thereby better reducing the power consumption of the motor and improving the operating efficiency of the entire unit.

[0124] In other embodiments, exemplarily, such as Figure 7 As shown, one connecting end of the fourth secondary drive shaft 1133 is connected to the third expander rotor 143, the two secondary connecting ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142, the two secondary connecting ends 115 of the second secondary drive shaft 1123 are respectively connected to the first air compressor rotor 121 and the second air compressor rotor 122, and the two secondary connecting ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132.

[0125] In other embodiments, exemplarily, such as Figure 8 As shown, one connecting end of the fourth secondary drive shaft 1133 is connected to the third expander rotor 143, the two secondary connecting ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142, the two secondary connecting ends 115 of the second secondary drive shaft 1123 are respectively connected to the first air compressor rotor 121 and the second nitrogen oxide compressor rotor 132, and the two secondary connecting ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second air compressor rotor 122.

[0126] In other embodiments, exemplarily, such as Figure 9As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the first air compressor rotor 121 and the second air compressor rotor 122; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142; one connection end of the second secondary drive shaft 1123 is connected to the third expander rotor 143; and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132.

[0127] In other embodiments, exemplarily, such as Figure 10 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142; one connection end of the second secondary drive shaft 1123 is connected to the third expander rotor 143; and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first air compressor rotor 121 and the second air compressor rotor 122.

[0128] In other embodiments, exemplarily, such as Figure 11 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the first air compressor rotor 121 and the second nitrogen oxide compressor rotor 132; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142; one connection end of the second secondary drive shaft 1123 is connected to the third expander rotor 143; and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second air compressor rotor 122.

[0129] In other embodiments, exemplarily, such as Figure 12 As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the second air compressor rotor 122 and the first air compressor rotor 121, the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the first expander rotor 141 and the second nitrogen oxide compressor rotor 132, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the first expander rotor 141.

[0130] In other embodiments, exemplarily, such as Figure 13As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132, the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the first air compressor rotor 121 and the second expander rotor 142, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first expander rotor 141 and the first air compressor rotor 121.

[0131] In other embodiments, exemplarily, such as Figure 14 As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second nitrogen oxide compressor rotor 132, the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the first air compressor rotor 121 and the second expander rotor 142, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the second nitrogen oxide compressor rotor 132 and the second air compressor rotor 122.

[0132] In other embodiments, exemplarily, such as Figure 15 As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second nitrogen oxide compressor rotor 132, the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the first air compressor rotor 121 and the second air compressor rotor 122, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second expander rotor 142.

[0133] In other embodiments, exemplarily, such as Figure 16 As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second air compressor rotor 122, the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the second expander rotor 142 and the first air compressor rotor 121, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132.

[0134] In other embodiments, exemplarily, such as Figure 17 As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second air compressor rotor 122, the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the second nitrogen oxide compressor rotor 132 and the first air compressor rotor 121, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second expander rotor 142.

[0135] In other embodiments, exemplarily, such as Figure 18 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the first air compressor rotor 121 and the third expander rotor 143; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142; one secondary connection end of the second secondary drive shaft 1123 is connected to the second air compressor rotor 122; and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132.

[0136] In other embodiments, exemplarily, such as Figure 19 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the first air compressor rotor 121 and the third expander rotor 143; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142; the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second air compressor rotor 122; and the secondary connection end 115 of the first secondary drive shaft 1122 is connected to the second nitrogen oxide compressor rotor 132.

[0137] In other embodiments, exemplarily, such as Figure 20 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the third expander rotor 143 and the first nitrogen oxide compressor rotor 131; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142; the secondary connection end of the second secondary drive shaft 1123 is connected to the second air compressor rotor 122; and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the second nitrogen oxide compressor rotor 132 and the first air compressor rotor 121.

[0138] In other embodiments, exemplarily, such as Figure 21 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the first expander rotor 141 and the first nitrogen oxide compressor rotor 131; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second expander rotor 142; the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the first air compressor rotor 121 and the second air compressor rotor 122; and the secondary connection end 115 of the first secondary drive shaft 1122 is connected to the second nitrogen oxide compressor rotor 132.

[0139] In other embodiments, exemplarily, such as Figure 22As shown, the secondary connection end 115 of the fourth secondary drive shaft 1133 is connected to the second air compressor rotor 122, the two secondary connection ends 115 of the third secondary drive shaft 1132 are connected to the first expander rotor 141 and the second expander rotor 142 respectively, the two secondary connection ends of the second secondary drive shaft 1123 are connected to the third expander rotor 143 and the first air compressor rotor 121 respectively, and the two secondary connection ends 115 of the first secondary drive shaft 1122 are connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132 respectively.

[0140] In other embodiments, exemplarily, such as Figure 23 As shown, the secondary connection end 115 of the fourth secondary drive shaft 1133 is connected to the rotor 132 of the second nitrogen oxide compressor. The two secondary connection ends 115 of the third secondary drive shaft 1132 are connected to the rotor 141 of the first expander and the rotor 142 of the second expander, respectively. The two secondary connection ends of the second secondary drive shaft 1123 are connected to the rotor 121 of the first air compressor and the rotor 122 of the second air compressor, respectively. The two secondary connection ends 115 of the first secondary drive shaft 1122 are connected to the rotor 131 of the first nitrogen oxide compressor and the rotor 143 of the third expander, respectively.

[0141] In other embodiments, exemplarily, such as Figure 24 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the third expander rotor 143 and the first air compressor rotor 121; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second air compressor rotor 122; the secondary connection end of the second secondary drive shaft 1123 is connected to the second expander rotor 142; and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first nitrogen oxide compressor rotor 131 and the second nitrogen oxide compressor rotor 132.

[0142] In other embodiments, exemplarily, such as Figure 25 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the third expander rotor 143 and the first nitrogen oxide compressor rotor 131; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second nitrogen oxide compressor rotor 132; the secondary connection end of the second secondary drive shaft 1123 is connected to the second expander rotor 142; and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the first air compressor rotor 121 and the second air compressor rotor 122.

[0143] In other embodiments, exemplarily, such as Figure 26As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the third expander rotor 143 and the first nitrogen oxide compressor rotor 131; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second nitrogen oxide compressor rotor 132; the secondary connection end of the second secondary drive shaft 1123 is connected to the second expander rotor 142; and the two secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the second nitrogen oxide compressor rotor 132 and the first air compressor rotor 121.

[0144] In other embodiments, exemplarily, such as Figure 27 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the third expander rotor 143 and the first nitrogen oxide compressor rotor 131. The two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second air compressor rotor 122. The two secondary connection ends of the second secondary drive shaft 1123 are connected to the second expander rotor 142 and the first air compressor rotor 121. The secondary connection ends 115 of the first secondary drive shaft 1122 are respectively connected to the second nitrogen oxide compressor rotor 132.

[0145] In other embodiments, exemplarily, such as Figure 28 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the third expander rotor 143 and the first nitrogen oxide compressor rotor 131; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second nitrogen oxide compressor rotor 132; the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the second expander rotor 142 and the first air compressor rotor 121; and the secondary connection end 115 of the first secondary drive shaft 1122 is connected to the second air compressor rotor 122.

[0146] In other embodiments, exemplarily, such as Figure 29 As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the first air compressor rotor 121 and the third expander rotor 143; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second air compressor rotor 122; the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the second expander rotor 142 and the first nitrogen oxide compressor rotor 131; and the secondary connection end 115 of the first secondary drive shaft 1122 is connected to the second nitrogen oxide compressor rotor 132.

[0147] In other embodiments, exemplarily, such as Figure 30As shown, the two secondary connection ends 115 of the fourth secondary drive shaft 1133 are respectively connected to the first air compressor rotor 121 and the third expander rotor 143; the two secondary connection ends 115 of the third secondary drive shaft 1132 are respectively connected to the first expander rotor 141 and the second nitrogen oxide compressor rotor 132; the two secondary connection ends of the second secondary drive shaft 1123 are respectively connected to the second expander rotor 142 and the first nitrogen oxide compressor rotor 131; and the secondary connection end 115 of the first secondary drive shaft 1122 is connected to the second air compressor rotor 122.

[0148] In other embodiments, exemplarily, such as Figure 31 As shown, the two secondary connection ends 115 of the third secondary drive shaft 1132 are connected to the first expander rotor 141 and the second expander rotor 142 respectively, the two secondary connection ends of the second secondary drive shaft 1123 are connected to the first air compressor rotor 121 and the second air compressor rotor 122 respectively, and the secondary connection end 115 of the first secondary drive shaft 1122 is connected to the first nitrogen oxide compressor rotor 131.

[0149] In other embodiments, exemplarily, such as Figure 32 As shown, the secondary connection end 115 of the fourth secondary drive shaft 1133 is connected to the third expander rotor 143, the two secondary connection ends 115 of the third secondary drive shaft 1132 are connected to the first expander rotor 141 and the second expander rotor 142 respectively, the two secondary connection ends of the second secondary drive shaft 1123 are connected to the first air compressor rotor 121 and the second air compressor rotor 122 respectively, and the secondary connection end 115 of the first secondary drive shaft 1122 is connected to the first nitrogen oxide compressor rotor 131.

[0150] Example 2

[0151] Please refer to the following: Figure 33 This application also provides a nitric acid production apparatus 1000, including the nitric acid production unit 100, oxidation furnace 200, heat exchanger 300 and absorption tower 400 in any of the above embodiments.

[0152] The oxidation furnace 200 is connected to the air compressor 120.

[0153] Specifically, the oxidation furnace 200 is located at the compressed air output end of the air compressor 120.

[0154] Oxidation furnace 200 is used to mix compressed air and ammonia to produce high-temperature nitrogen oxide gas.

[0155] The heat exchanger 300 is connected to the nitrogen oxide compressor 130 and the oxidizer 200.

[0156] Specifically, the heat exchanger 300 is installed at the high-temperature nitrogen oxide gas output end of the oxidizing furnace 200. The heat exchanger 300 is used to cool the high-temperature nitrogen oxide gas. The heat exchanger 300 is also installed at the gas input end of the nitrogen oxide compressor 130.

[0157] The absorption tower 400 is connected to the nitrogen oxide compressor 130 and the expander 140.

[0158] Specifically, the absorption tower 400 is located at the compressed gas output end of the nitrogen oxide compressor 130, and the expander 140 is located at the tail gas output end of the absorption tower 400.

[0159] The compressed nitrogen oxide gas produced by the nitrogen oxide compressor 130 is fed into the absorption tower 400 to produce nitric acid, and the tail gas produced by the absorption tower 400 is supplied to the expander 140 to perform work.

[0160] It should be noted that please refer to the following: Figure 1 and Figure 12 In related technologies, steam turbines are used as the drive module. Since steam turbines require a certain amount of steam to operate, these technologies typically include a boiler to produce a specific amount of steam to power the turbine. Before the nitric acid production unit is started, the oxidizer cannot generate enough heat to supply the steam boiler for steam production. Therefore, additional steam is needed to drive the turbine during startup. Only after the entire system is fully operational can the self-sufficiency of steam required to drive the turbine be achieved. This not only makes the entire system more complex but also adds numerous large pieces of equipment.

[0161] In response to the above problems, such as Figure 33 As shown, the drive module 110 of this application uses an electric motor 111 for its drive unit, replacing the steam turbine in the related art. Thus, at the initial startup of the nitric acid production unit 100, the nitric acid production unit 100 drives the air compressor 120, the nitrogen oxide compressor 130, and the expander 140 via the electric motor. This replaces the operation method in the related art, which requires additional steam to drive the steam turbine, which in turn drives the air compressor, nitrogen oxide compressor, and expander. Furthermore, it eliminates the need for additional steam-generating equipment such as boilers, simplifying the overall composition of the nitric acid production unit 1000.

[0162] In addition, when the oxidizer 200 can generate heat to supply the boiler to produce steam, the steam enters the expander 140 to do work and is then discharged into the atmosphere. The motor is mainly used to drive the air compressor 120 and the nitrogen oxide compressor 130 to compress the gas and do work.

[0163] The work done by expander 140 supplements the compression work required by the unit (the power needed by air compressor 120 and nitrogen oxide compressor 130 to compress gas), thereby reducing the power consumption of the motor and improving the overall operating efficiency of the unit. Essentially, the motor and expander 140 act as power sources, performing work and supplying it to air compressor 120 and nitrogen oxide compressor 130 to provide them with the energy for compressing gas.

[0164] The entire equipment process is relatively simple and efficient. The heat exchanger 300 can be replaced by a boiler to produce steam to drive the expander 140. Especially during the start-up phase of the entire unit, there is no need to obtain additional steam through other methods to provide steam for turbine drive during unit startup.

[0165] This application also provides a method for producing nitric acid, which is achieved by the aforementioned nitric acid production apparatus 1000. The nitric acid production method flow is as follows:

[0166] Step S10: Normal pressure air is compressed by air compressor 120.

[0167] Specifically, the air compressor 120 compresses the air to a certain pressure.

[0168] It should be noted that at the beginning of the nitric acid production unit 1000 startup, the air compressor 120 is driven by an electric motor. When the oxidizer 200 or heat exchanger 300 can generate sufficient high-temperature and high-pressure gas, the electric motor and expander 140 act as power sources to do work and deliver it to the air compressor 120, providing it with the energy to compress the gas.

[0169] In step S20, compressed air is mixed with ammonia and then fed into oxidation furnace 200 for processing to obtain nitrogen oxide gas.

[0170] The compressed air is mixed with ammonia and then enters the oxidizer 200 for combustion to produce nitrogen oxides. The nitrogen oxide gas is cooled by the heat exchanger 300 and then enters the nitrogen oxide compressor 130 for compression.

[0171] Ammonia can be supplied by ammonia production equipment in the production plant.

[0172] In step S30, the nitrogen oxide gas is cooled by heat exchanger 300.

[0173] In step S40, the cooled nitrogen oxide gas is compressed in the nitrogen oxide compressor 130.

[0174] It should be noted that at the initial startup of the nitric acid production unit 1000, the nitrogen oxide compressor 130 is driven by an electric motor. When the oxidizer 200 or heat exchanger 300 can generate sufficient high-temperature and high-pressure gas, the electric motor and expander 140 act as power sources to perform work and supply it to the nitrogen oxide compressor 130, providing it with the energy to compress the gas.

[0175] In step S50, the compressed nitrogen oxide gas is introduced into the absorption tower 400 to produce nitric acid.

[0176] In step S60, the gas escaping from the top of the absorption tower 400 is processed and used as the gas source for the expander 140 to drive the expander 140 to do work and deliver it to the air compressor 120 and the nitrogen oxide compressor 130. The steam generated during the cooling process can also be used as the gas source for the expander 140 to drive the expander 140 to do work and deliver it to the air compressor 120 and the nitrogen oxide compressor 130.

[0177] It should be noted that at the initial startup of the nitric acid production unit 1000, the expander 140 is driven by an electric motor. When the oxidizer 200 or heat exchanger 300 can generate sufficient high-temperature and high-pressure gas, the expander 140 is driven by the high-temperature and high-pressure gas to perform work and output power to the air compressor 120 and the nitrogen oxide compressor 130.

[0178] The gas (tail gas) escaping from the top of the absorption tower 400 is treated and then used as the gas source to drive the expander 140 to do work and deliver it to the air compressor 120 and the nitrogen oxide compressor 130. The motor and the expander 140 work together as a power source to do work and deliver it to the air compressor 120 and the nitrogen oxide compressor 130, providing them with the energy to compress the gas.

[0179] In addition, the steam generated by the heat exchanger 300 during the heat exchange process can also serve as a gas source for the expander 140 to drive the expander 140 to do work and deliver it to the air compressor 120 and the nitrogen oxide compressor 130. The motor and the expander 140 work together as a power source to do work and deliver it to the air compressor 120 and the nitrogen oxide compressor 130, providing them with the energy to compress the gas.

[0180] It should be noted that in related technologies, the steam generated during the cooling process of heat exchanger 300 is usually used as the driving gas source for steam turbine.

[0181] In this embodiment, since a steam turbine is not used, the steam generated during the cooling process of the heat exchanger 300 is used as the gas source for the expander 140 to avoid waste. The steam drives the expander 140 to do work and outputs it to the air compressor 120 and the nitrogen oxide compressor 130, which can reduce the energy loss of the motor and thus reduce the energy loss of the nitric acid production unit 1000, making it more energy-efficient.

[0182] Optionally, the gas source for the expander 140 can be any one or any combination of the gas escaping from the top of the absorber 400 (tail gas), the steam generated during the cooling process of the heat exchanger 300, and other external gas sources. This ensures that the expander 140 has a sufficient gas supply, such as... Figure 7 to Figure 11 As shown, increasing the number of expander rotors greatly improves the work capacity of expander 140, allowing the work done by expander 140 to supplement the compression work required in the unit (the power required by air compressor 120 and nitrogen oxide compressor 130 to compress gas), further reducing the power consumption of the motor and improving the operating efficiency of the entire nitric acid production unit 1000.

[0183] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0184] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A nitric acid production unit, characterized in that, include: Air compressor; Nitrogen oxide compressor; Expander; A drive module includes a drive motor and at least two primary drive shafts, the at least two primary drive shafts being respectively connected to the drive motor, and the at least two primary drive shafts having at least three primary connection ends, the primary connection ends being connected to one or two of the air compressor, the nitrogen oxide compressor and the expander; The drive module includes the drive motor, a first primary drive shaft and a second primary drive shaft. The first primary drive shaft and the second primary drive shaft are respectively connected to the drive motor. The first primary drive shaft has at least two primary connection ends, and the second primary drive shaft has at least one primary connection end. Each primary connection end is connected to one or two of the air compressor, the nitrogen oxide compressor and the expander.

2. The nitric acid production unit according to claim 1, characterized in that, The drive module also includes: The first gearbox includes a first gear shaft, a first secondary drive shaft, and a second secondary drive shaft. The first gear shaft has two primary connection ends and an input end. The input end of the first gear shaft is connected to the first primary drive shaft. One primary connection end of the first gear shaft is connected to the first secondary drive shaft, and the other primary connection end is connected to the second secondary drive shaft.

3. The nitric acid production unit according to claim 2, characterized in that, The drive module also includes: The second gearbox includes a second gear shaft and a third secondary transmission shaft. The second gear shaft has a primary connection end and an input end. The input end of the second gear shaft is connected to the second primary transmission shaft, and the primary connection end of the second gear shaft is connected to the third secondary transmission shaft. or; The second gearbox includes a second transmission shaft, a third secondary transmission shaft, and a fourth secondary transmission shaft. The second transmission shaft has two primary connection ends and an input end. The input end of the second transmission shaft is connected to the second primary transmission shaft. One primary connection end of the second transmission shaft is connected to the third secondary transmission shaft, and the other primary connection end is connected to the fourth secondary transmission shaft.

4. The nitric acid production unit according to claim 3, characterized in that, The air compressor includes at least one air compressor rotor; The nitrogen oxide compressor includes at least one nitrogen oxide compressor rotor; The expander includes at least one expander rotor, and each rotor of the air compressor, the nitrogen oxide compressor and the expander is connected to one of the first secondary drive shaft, the second secondary drive shaft and the third secondary drive shaft.

5. The nitric acid production unit according to claim 4, characterized in that, The first secondary drive shaft, the second secondary drive shaft, and the third secondary drive shaft are each provided with two secondary connection ends, and the first secondary drive shaft, the second secondary drive shaft, and the third secondary drive shaft are provided with a total of six secondary connection ends.

6. The nitric acid production unit according to claim 5, characterized in that, The air compressor includes a first air compressor rotor and a second air compressor rotor; The nitrogen oxide compressor includes a first nitrogen oxide compressor rotor and a second nitrogen oxide compressor rotor; The expander includes a first expander rotor and a second expander rotor, wherein... The first air compressor rotor is connected to one of the six secondary connection terminals, the second air compressor rotor is connected to one of the remaining six secondary connection terminals, the first nitrogen oxide compressor rotor is connected to one of the remaining six secondary connection terminals, the second nitrogen oxide compressor rotor is connected to one of the remaining six secondary connection terminals, the first expander rotor is connected to one of the remaining six secondary connection terminals, and the second expander rotor is connected to one of the remaining six secondary connection terminals.

7. The nitric acid production unit according to any one of claims 1 to 6, characterized in that, The drive unit is an electric motor; both the air compressor and the nitrogen oxide compressor are centrifugal compressors; the expander is a centripetal or axial flow expander.

8. The nitric acid production unit according to claim 4, characterized in that, Both the air compressor and the nitrogen oxide compressor have a two-stage or higher compression structure, and the air compressor has at least two rotors and the nitrogen oxide compressor has at least two rotors. The expander has a two-stage or higher expansion structure, and the number of expander rotors is at least two.

9. The nitric acid production unit according to claim 4, characterized in that, The air compressor rotor, the nitrogen oxide compressor rotor, and the expander rotor are not coaxial with the drive motor.

10. A nitric acid production apparatus, characterized in that, include: The nitric acid production unit according to any one of claims 1 to 9; An oxidation furnace is connected to the air compressor; A heat exchanger connects the nitrogen oxide compressor and the oxidation furnace; The absorption tower is connected to the nitrogen oxide compressor and the expander.

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